I once tapped a guy who weighed 280 lbs just by sitting on his stomach. Ass-on-belly. Essentially had him mounted, facing the opposite way, looking for a leg submission when he starts slapping me on the back.

I turn around and he gasps "TAP! TAP!"

I got off and was like ".... you sure?" "Yeah."

Weirdest submission I've gotten so far.

Thanks for the replies on my behalf, too. I've been caught with that a bunch.

controlling knee on the belly of obviously much easier in gi (with grips and chokes available) than without gi. Often times you can slip out of a no gi knee on the belly.

That being said, if his pressure is off, you can try to elbow escape hard away from him (i.e. your stomach faces him) while you attack and wrap the leg thats on your stomach with your top arm (your top arm after escaping hard to your side). As Yrkoon pointed out, this will kinda get you to your knees/ turtling position, however now you have a leg that you can attempt to stand up with for a single leg takedown (and hopefully reverse the entire situation).

anyways, 2nd post by JohnnyS has worked wonders for me, also check out SM's post

"Labor is prior to, and independent of, capital. Capital is only the fruit of labor, and could never have existed if labor had not first existed. Labor is the superior of capital, and deserves much the higher consideration." -A. Lincoln